Talked to a company recruiter first, he explained what the company was and does and then asked if I had any questions. Next I was scheduled for a phone interview with the hiring manager. After that I was scheduled for four separate on-site interviews with the same hiring manager, an engineer, the EHS team, and an HR person. There was also a tour of the facility. The on-site interviews and tour took about 4-5 hours in total. Was ghosted afterwards and haven't heard from them since.